Slate has an interesting article on Congressional staffers during the August recess.
The Congressional staff is one of the most interesting aspects of American politics. Unlike the few, the connected, or the simply lucky who become White House staffers by hitching to the right horse at the right time, they are usually ambitious, politically-minded, freshly graduated 20-somethings, ready to take on the world and make a difference. Many only stay for a few years, put it on a resume, and move on to different Beltway interests or law/business school. Some stick around for the long haul, becoming Chiefs of Staff to the congresspeople or members of the staffs of powerful committees. By that time, they'll usually have J.D.'s and street creds, and they'll be doing a lot of the actual writing of legislation. I have a friend who just transferred from working in Sen. Evan Bayh's office after a few years as an assistant to the Chief of Staff. She never realized that around the Hill, his was considered to be an incredibly intense office. Now, when she says to other people working for Representatives in the Cannon House Office Building that she worked on Senator Bayh's staff, she gets the "Wow...that's impressive" treatment.
They spend their days answering calls, telling the congresspeople where to be and when, reminding them how to vote, and driving them between places. Oftentimes, they are there late into the night and sometimes on weekends--long after the elected officials are gone. Ultimately, the work of Congress couldn't happen without them, or, at the very least, the work would be even slower than it already is. In some ways, they are a neat outcropping of our system. In some ways, it's kind of creepy that random, unelected young people are that close to power. No matter, though, because somehow it works, and it has for decades.